1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef BASE_MAC_SCOPED_NSEXCEPTION_ENABLER_H_ 6 #define BASE_MAC_SCOPED_NSEXCEPTION_ENABLER_H_ 7 8 #import <Foundation/Foundation.h> 9 10 #include "base/base_export.h" 11 #include "base/basictypes.h" 12 13 namespace base { 14 namespace mac { 15 16 // BrowserCrApplication attempts to restrict throwing of NSExceptions 17 // because they interact badly with C++ scoping rules. Unfortunately, 18 // there are some cases where exceptions must be supported, such as 19 // when third-party printer drivers are used. These helpers can be 20 // used to enable exceptions for narrow windows. 21 22 // Make it easy to safely allow NSException to be thrown in a limited 23 // scope. Note that if an exception is thrown, then this object will 24 // not be appropriately destructed! If the exception ends up in the 25 // top-level event loop, things are cleared in -reportException:. If 26 // the exception is caught at a lower level, a higher level scoper 27 // should eventually reset things. 28 class BASE_EXPORT ScopedNSExceptionEnabler { 29 public: 30 ScopedNSExceptionEnabler(); 31 ~ScopedNSExceptionEnabler(); 32 33 private: 34 bool was_enabled_; 35 36 DISALLOW_COPY_AND_ASSIGN(ScopedNSExceptionEnabler); 37 }; 38 39 // Access the exception setting for the current thread. This is for 40 // the support code in BrowserCrApplication, other code should use 41 // the scoper. 42 BASE_EXPORT bool GetNSExceptionsAllowed(); 43 BASE_EXPORT void SetNSExceptionsAllowed(bool allowed); 44 45 // Executes |block| with fatal-exceptions turned off, and returns the 46 // result. If an exception is thrown during the perform, nil is 47 // returned. 48 typedef id (^BlockReturningId)(); 49 BASE_EXPORT id RunBlockIgnoringExceptions(BlockReturningId block); 50 51 } // namespace mac 52 } // namespace base 53 54 #endif // BASE_MAC_SCOPED_NSEXCEPTION_ENABLER_H_ 55
